Body Mass Index
What is Body Mass Index?
Calculate Body Mass Index:
- Online with our BMI Calculator
- Online with our interactive BMI Charts
- Manually using the BMI formula
- On a Windows PC using our free BMI Calc software
Body Mass Index (BMI) measures a persons weight relative to their height. The Body Mass Index Formula was developed by Belgium statistician Adolphe Quelet .
The formula is designed for adults over 20 years old. Once calculated, Body Mass Index can be compared to weight status categories to determine if an individual is:
- underweight (BMI: below 19.5)
- normal weight (BMI:18.5 - 24.9)
- overweight (BMI: 25.0 to 29.9)
- obese (BMI: 30.0 & above)
Large health organizations have used/use different weight status categories. Weight status categories on this site are in keeping with the US Centers for Disease Control & Prevention guidelines.
Limitations of Body Mass Index
An individuals Body Mass Index and their corresponding 'weight status' category needs to be placed in context.
Body Mass Index can:
- Overestimate Body Fat
- Individuals who are athletic and/or have a muscular build may be categorized as overweight. Body builders are often categorized as obese - however body building may promote a longer life expectancy.
- Underestimate Body Fat
- Body fat can be underestimated in individuals who have lost muscle mass - this often occurs with older people.
Diseases Associated with Obesity
In general, the greater the BMI the greater the risk of contracting diseases associated with obesity. These diseases include:
- High Blood Pressure - which can lead to heart failure, stroke, kidney damage and/or loss of vision due to retinal damage.
- Diabetes - a metabolic disease caused by lack of insulin
- Arteriosclerosis - narrowing & thickening of the arteries which can cause cerebrovascular and coronary disorders.
- Hyperlipemia - a high level of fat in the blood which is associated with high cholesterol levels.
Other Risk Factors
Body Mass Index is not a diagnostic tool, it is an indicator of weight status. The risk factors below should also be considered when assessing general health risks.
- Family History of premature heart disease
- High Blood Pressure(hypertension)
- High LDL-cholesterol
- HDL-Cholesterol
- Triglycerides
- High Blood Glucose (sugar)
- Physical inactivity
- Cigarette/Tobacco Smoking
